This PR brings the latest changes in Flow to master.
This version is the minimal requested to run CUPyDO-v1.0
Modifications
Split Solver class into Newton and Picard classes, user can choose the algorithm as they see fit
Improved polar scripts, the solver and the problem are not re-initialized at every change in angle of attack
Created template functions in python calling the C++ classes and functions used in the tests, if the C++ code changes, then there is only one python file to adapt
Tests are passing on debian-4.9 (gaston), ubuntu-16.04 (shippable, no Trilinos) and ubuntu-18.04 (my VM)
Comments
Regarding the template functions I created for flow tests and validation (flow/template.py): I am not sure about this new method, I will probably refactor it into real python API in the future
Regarding the CODEOWNERS file: this is a test, I will try to PR without adding any reviewers
